Italian Prime Minister Matteo Renzi has asked fellow EU leaders to hold an emergency meeting on immigration this week following the latest migrant drownings, Renzi's spokesman said on Sunday.

As many as 700 people were feared dead after a fishing boat packed with migrants capsized off the Libyan coast overnight, in what may be one of the worst disasters of the Mediterranean migrant crisis, officials said.

In contacts with several EU leaders on Sunday Renzi called for an emergency summit this week to discuss the mounting migrant crisis, Renzi's spokesman told Reuters. Renzi was to hold a cabinet meeting later on Sunday, followed by a news conference at 1600 GMT. (Reporting By Gavin Jones; Editing by Jon Boyle)